Blasting cap



June 6, i933. W T AYER 1,912,423

BLASTING CAP Filed Deo. l2, 1951 Patented .lune 6, i933 istanza NT@ TTES.PATENT @FFEQ WILLIAM T. AYER, OF WILMINGTON, DELAWARE, ASSGNOR TOHERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION FDELAWARE BLASTINC CAP Application led December 12, 1931.

This invention relates to an improvement in blasting caps such as areused in the firing of commercial explosives, and more particularlyrelates to4 an arrangement whereby 5 blasting caps may be protectedduring shipment and storage with avoidance of accidental discharge.

As is well known, blasting caps adapted for electrical firing areequipped with a pair of lead wires by which they are connected into afiring circuit after they are placed within an explosive charge to befired.- Customarily for shipment and storage of such caps the lead wiresare bundled and tied centrally of the bundle and with the free ends ofthe lead wires and the cap at oppo site ends of the bundle.

The customary bundling and tying of the lead wires of such caps isordinarily sutlicient to Aenable convenient packaging and handling ofthe caps, but since the cap itself is wholly unprotected, it is liableto accidental firing by any shock to which it may be subjected, as forexample, by striking another cap in a package, or by striking the wallof a package during shipment, from being dropped in handling, orotherwise. As will be appreciated, such caps are usually loaded withfulminate of mercury, which is 0 very sensitive and which is of greatpower so that the possibility of accidental firing presents a largerisk.

Now, it is the object of this invention to provide an arrangementwhereby such caps will be adequately protected from shock,

whether during shipment, in storage, or in handling, until it is desiredto prepare them for use.

In accordance with this invention there is provided a protector for thecap in the form of a sleeve, which is slipped over the cap and leadwires bundled in the customary manner, the protector or sleeve beingretained and being made of any suitable ma- 45 terial and being retainedin position at one end by turns o f the end portions of the lead wiresabout the bundle and at the other end by bending one or more of thelengths of the bundle over the end of the protector.

Having now indicated in a general way Serial No. 580,557.

the nature and purpose of my invention, l will proceed to a detaileddescription of preferred embodiments thereof with reference to theaccompanying drawing in which:

Figure 1 is a side View of a blasting cap embodying my invention.

Figure 2 is a plan view showing a blasting cap and modified form ofprotector for application thereto.

Figure 3 is an end view of the arrangement shown in Figure l, theprotector being of the form shown in Figure 2.

Figure 4 is a perspective View of a form of protector.

Figure 5 is an end View of the arrangement shown in Figure l, theprotector being of the form shown in Figure 4. i

Referring more particularly to Figures 1, 4 and 5, A indicates ablasting cap, provided with lead wires which 'are bent back and forth inlengths b, b to form a bundle. In forming the bundle the lengths arearranged so that the cap A lies on the bundle roughly between the middleand one end of the bundle and a free end portion is turned about thebundle roughly at its middle acting to tie the bundle and as a stop forthe protector, as will be described. The turns of the free end portionof the wires about the bundle are shown at C.

As is customary, the lead Wires are insulated except adjacent their freeends, by which they are connected into a firing circuit. The insulatedend portions of the Wires are desirably shunted by means of a Vmetal, orconducting clip D, or otherwise as by twisting together, in order toprevent accidental iiring of the cap through contact of the uninsulatedportions of the wires with any solirce of current.

The protector` E is made of any suitable material, as fibre, bakelite,cloth covered metal, etc., etc., is in the form of a sleeve of a lengthat .least equal to and desixably in excess of that of the cap. In crosssection the protector or sleeve E may be generally circular, as shown inFigure 4, or it may be of any other form as, for example, polygonal. Theprotector will, however, be of sufficient area in cross section to slip,lo(

freely or with relative ease, over the cap and bundled lead wires, intoa position covering the cap and with its inner end abutting the turn Dof the lead wires, as shown in Figure With the protector in the positionshown in Figure 1, the end ,portion of a length or lengths b of thebundled lead Wires is bent over the end of the protector or sleeve E toretain it in place.

Referring now to Figures protector E is formed from a metal f, thesurfaces of which arecoveref. with cloth g, suitably adhered thereto.

The application of the protector E to the cap is eii'ected by bendingthe protector 2 and 3, the light sheet of about the cap and bundle toform a sleeve, P

which may be accomplished manually or by any suitable bending mechanism.The lprotector E may be held in place as shown in Figure l.

As will be obvious, removed from the cap bysimply drawing 1t off withthe fingers and the cap may, after removal of the protector, be preparedfor use as usual.

It will be understood that it is not contemplated that this inventionshall be limited to details described herein for the purpose ofillustration and fullnessof disclosure, since it will be appreciatedthat various modifications in detail may be made. Thus, for example, theprotector may be retained in position embracing the cap and bundleadjacent thereto by various means.

What I claim and desire toy protect by Letters Patent is:

1. In combination, a `blasting wires extending from the cap and bundledtherewith by bending back and forth into lengths, and a protector formedfrom cushioning material and loosely embracing the cap and the bundle oflead wires adjacent thereto.

2. In combination, a blasting cap, lead wires extending from the cap andbundled therewith by bending back and forth into lengths, a protectorformed from cushioning material and loosely embracing the cap an thebundle of lead wires` adjacent thereto and means for retaining theprotector in position. i

3. In combination, a blasting cap, lead wires extending from the cap andbundled therewith by bending back and forth into lengths, a free endportion of the lead Wires being turned about the bundle, and a protectorformed from cushioning material and loosely embracing the cap and thebundle of lead wires adjacent thereto and having one of its endsadjacent to said turns about the bundle.

4. In combination,

the protector may b e wires extendingV Jfrom the cap and" bundled andforth into thnmwith by bending back tof lead Wires adjacent thereto,

cap, lead lengths, and a protector formed from cushioning material andloosely embracing the cap and the bundle of lead Wires adjacent thereto,one of the lengths forming the bundle being bent over an end of theprotector.

5. In combination, a blasting cap, lead Wires extending from the" capand bundled therewith by bending back and forth into lengths, a free endportion of the lead Wires being turned about the bundle, and a protectorformed from cushioning material and loosely embracing the cap and thebundle said turns acting as a stop, for the protector in one directionand one of the lengths JI'orming the bundle being bent over an end ofthe rotector and acting as a stop for the protector in the oppositedirection.

In testimony of which invention, I have hereunto set my hand, atWilmington, Delaware, on this 9 day of December, 1931.

WILLIAM T. AYER.

a blasting cap, lead

